KR101683446B1 - Apparatus and system comprising collapsing and extending mechanisms for actuating engine valves - Google Patents

Abstract

An apparatus and system for operating one or more engine valves includes a rocker arm having a folding mechanism and an extension mechanism. The rocker arm may be configured as an exhaust rocker arm or an intake rocker arm. The folding mechanism is disposed in operation to receive the end of the rocker arm and is configured to receive operation from a main valve actuation source. The extension mechanism is disposed in the rocker arm and is configured to carry auxiliary valve actuation operations to the one or more engine valves. In the first embodiment, the extension mechanism is disposed at the valve movable end of the rocker arm, whereas in the second embodiment, the extension mechanism is disposed at the operational receiving end of the rocker arm. The supply of fluid to the first and second fluid passages respectively controls the operation of the extension and folding mechanisms.

Description

[0001] APPARATUS AND SYSTEM COMPRISING COLLAPSING AND EXTENDING MECHANISMS FOR ACTUATING ENGINE VALVES [0002] BACKGROUND OF THE INVENTION [0003]

Cross-reference to related application

This application claims the benefit of US Provisional Patent Application Serial No. 61 / 912,535 entitled " INTEGRATED ROCKER SYSTEM ", filed December 5, 2013, Quot; DOUBLE ROLLER ROCKER WITH LOBE DEACTIVATION AND AUXILIARY VALVE MOTION PICK-UP ", which claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 052,100, filed on September 18, 2014, These teachings are incorporated herein by reference.

The present disclosure relates generally to internal combustion engines and, more particularly, to an apparatus and system for operating engine valves.

Internal combustion engines typically use mechanical, electrical, or hydro-mechanical valve actuation systems to drive engine valves. These systems may include a combination of camshafts, rocker arms, and pushrods driven by crankshaft rotation of the engine. When the camshaft is used to actuate the engine valves, the timing of valve actuation can be fixed by the size and position of the lobes (i.e., the cams) of the camshaft.

For each 360 degree rotation of the camshaft, the engine completes a complete cycle of four strokes (i.e., expansion, exhaust, intake and compression). Both the intake and exhaust valves can be closed and remain closed for most of the expansion stroke and the piston moves away from the cylinder head (i.e., the volume between the cylinder head and the piston head Is increased). During positive power operation, the fuel is burned during the expansion stroke and positive power is delivered to the engine. The expansion stroke ends at the bottom dead center, at which time the piston is reversed in direction and the exhaust valve can be opened for the main exhaust event. The lobe of the camshaft may be synchronized to open the exhaust valve for the main exhaust event when the piston moves upward and forces combustion gases out of the cylinder.

Although not required, additional auxiliary valve events may be desirable and it is known to provide alternative flow control of the gas through the internal combustion engine, for example to provide vehicle engine braking. Such as compression-release (CR), engine braking, bleeder engine braking, exhaust gas recirculation (EGR), brake gas recirculation (BGR), or other auxiliary valve events It may be desirable to actuate the exhaust valves. It will also be appreciated that other types of exhaust valves may be used, such as, but not limited to, early intake valve opening (EIVC), late intake valve closing (LIVC), early exhaust valve opening (EEVO) Other positive power valve operations, which are generally classified as variable valve actuation (VVA) events, may also be desirable. Still further, it has been found that cylinder deactivation (or variable displacement), in which the engine valves remain closed and fuel is not provided to a given cylinder, thereby effectively removing the cylinder from positive power production, Lt; / RTI >

One way to adjust the valve timing and lift given to the fixed cam profile was to include a loss operating device of the valve train coupling between the valve and the cam. The loss operation is a term applied to a class of technical solutions for modifying valve operation indicated by a fixed cam profile with a variable length mechanical, hydraulic or other coupling subassembly. In a lossy motion system, the cam lobe can provide the maximum dwell (time) and maximum lift motion required over the entire range of engine operating conditions. The variable length system may be included in the cam that provides the maximum operation to subtract or "lose " some or all of the action imparted to the valve by the cam and the valve train engagement which is the middle of the valve to be opened. Such a variable length system, or lossy operating system, when fully inflated, can deliver the entire cam action to the valve and can deliver minimal or no cam action to the valve when fully retracted.

These known prior art systems are particularly advantageous in the case of heavier loads that require more braking power than is currently available in the case of engines of reduced size and / or by conventional decompression engine braking, It may not provide power. It is known that engine braking valve operation by a second decompression event (i.e., two-stroke engine braking) can provide the necessary braking power from the engine brake. Unfortunately, however, most engines do not have enough space to include the various aforementioned auxiliary valve events, particularly the components necessary to carry out those associated with two-stroke engine braking. To overcome these spatial problems, it is possible to include these components in relatively large (and consequently expensive) overhead housings.

Accordingly, it would be advantageous to provide solutions for engine braking and other ancillary valve movement systems that overcome the limitations of conventional systems.

The present disclosure describes an apparatus and system for operating one or more engine valves based on a rocker arm having a collapsing mechanism and an extending mechanism. The rocker arm may be configured as an exhaust rocker arm or an intake rocker arm. The folding mechanism is disposed in operation to receive the end of the rocker arm and is configured to receive operation from a main valve actuation source. The folding mechanism may include a contact surface for receiving main valve actuation operations from a main valve actuation source. The extension mechanism is disposed in the rocker arm and is configured to carry auxiliary valve actuation operations to the one or more engine valves. In the first embodiment, the extension mechanism is disposed at the valve movable end of the rocker arm, whereas in the second embodiment, the extension mechanism is disposed at the operational receiving end of the rocker arm. The first fluid passageway communicates with the extension mechanism and the second fluid passageway communicates with the folding mechanism. The supply of fluid to the first and second fluid passages respectively controls the operation of the extension and folding mechanisms.

In the first embodiment, the extension mechanism can be configured to actuate only the first engine valve of the one or more engine valves in accordance with the auxiliary valve actuation operations, while the main valve actuator at the valve end of the rocker arm, May be configured to actuate one or more engine valves in accordance with the main valve actuation operations. Also according to the first embodiment, the rocker arm may include a stationary member disposed at the operative receiving end of the rocker arm and including a contact surface for receiving auxiliary valve actuating operations from an auxiliary valve actuating source of operation. In a second embodiment, the extension mechanism may include a contact surface for receiving auxiliary valve actuation operations from an auxiliary valve actuation source.

In the first or second embodiment, the control valve is provided for supplying fluid to and checking fluid against the first fluid path, and for venting fluid from the first fluid path when the source of fluid to the control valve is removed . Additionally, the control valve may be used to supply fluid to the second fluid passage, which may be timed or staged after the supply of fluid to the first fluid passage. In this manner, a single fluid supply source may be used in conjunction with the control valve for supplying to both the first and second fluid passages. Alternatively, the first and second fluid supply sources may be used to supply fluid to the first and second fluid passages, respectively. In a first embodiment, the control valve may also be configured to supply fluid to the contact surface of the stationary member.

The features described in this disclosure are specifically set forth in the appended claims. These features will become apparent from consideration of the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings, wherein like numerals refer to like elements.

1 is a schematic block diagram of an apparatus and system for operating engine valves in accordance with a first embodiment of the present disclosure,
Figure 2 is a schematic block diagram of an apparatus and system for operating engine valves according to a second embodiment of the present disclosure,
Figures 3 and 4 are respectively a plan and perspective bottom views of the implementation of the rocker arm according to the first embodiment of the present disclosure,
Figures 5 and 6 are side views of the implementation of Figures 3 and 4 illustrating the operation of the rocker arm,
Figure 7 is a partial side elevational view of the implementation of Figures 3 and 4 further illustrating an example of an extension mechanism and fluid supply components,
Figures 8 and 9 are enlarged cross-sectional views of a control valve that may be used as a fluid supply component in accordance with various embodiments described herein,
10 is an enlarged cross-sectional view of an alternative control valve that may be used as a fluid supply component in accordance with various embodiments described herein,
11 is a plan perspective view of the execution of the exhaust and intake rocker arms according to the second embodiment of the present disclosure,
Figures 12 and 13 are plane perspective, partial cross-sectional views of the implementation of Figure 11, further illustrating an example of a folding mechanism,
Figures 14 and 15 illustrate examples of cam profiles and valve movements in accordance with the present disclosure.

1 illustrates a schematic block diagram of an apparatus 102 and a system 100 for operating engine valves in accordance with a first embodiment of the present disclosure. In particular, the system 100 includes a rocker arm 102, a main valve operating source 104, an auxiliary valve actuation operation source 106, one or more engine valves 108, and one or more fluid supply sources 110). As used herein, the phrase "predominant" refers to the features of this disclosure relating to so-called main event engine valve operations, ie, valve operations used during positive power generation, while the phrase "auxiliary" (I.e., internal EGR) valve operations that are used during engine operation (e.g., engine braking) other than positive power generation, or positive power generation. The rocker arm 102, which may be configured as an exhaust rocker arm or an intake rocker arm, includes an operational receiving end 112 and a valve movable end 114, with their respective ends 112,114, And the rocker arm 102 is reciprocated about the axis. As known in the art, the rocker arm 102 is reciprocally movable along valve operations received at the operative receiving end 112 from the main valve operating source 104 and / And delivers these received valve operations to one or more engine valves 108 via valve actuation end 114.

The valve operating sources 104, 106 may include any type of operating source used to provide the desired engine valve operations as is known in the art. For example, in one embodiment, the valve actuation operation sources 104, 106 may include cams in one or more overhead camshafts. Alternatively, the valve actuation operation sources 104, 106 may include push rods as in the case of an overhead valve configuration. Regardless, the one or more engine valves 108 are typically poppet-type valves with appropriate valve springs for biasing the valves to the closed position. As is known in the art, a valve bridge can be used to control the application of valve operations to a plurality of engine valves through a single rocker arm. The fluid supply source (s) 110 may be any of a variety of fluid supply sources (s) 110 that may be used to control the pivoting and hydraulically extending and collapsing mechanisms through the first and second fluid passages 120, 122, respectively, Of suitable fluid. In an embodiment, the fluid supply source (s) 110 may comprise one or more sources of low-pressure engine oil. As illustrated in Figure 1, the fluid supply source (s) 110 may be external to the rocker arm 102, or alternatively, the fluid supply source (s) 110 ' Elements, examples of which are described in further detail below.

The rocker arm 102 of the first embodiment includes an extension mechanism 116 disposed at the valve movable end 114 of the rocker arm 102 and a folding mechanism 118 disposed at the operational receiving end 112 of the rocker arm 102 ). In general, the extension mechanism 116 and the folding mechanism 118 may be configured to maintain or withdraw the retracted condition when not deployed, or may not deliver an input action through the mechanism when extended, Includes devices capable of maintaining an extended state when deployed and also carrying valve actuation operations in their extended states. 1, there is also provided a first fluid passage 120 in fluid communication between the fluid supply source (s) 110, 110 'and the extension mechanism 116, and the fluid supply source (s) 110, 110 ') and a folding mechanism (118). In the embodiment, the extension mechanism 116 and the folding mechanism 118 are controllable in opposite manners, although they may operate similarly. That is, in one state (e.g., positive power generation), the folding mechanism 118 is controlled to be in its extended or locked state and the extension mechanism 116 is controlled to be in its retracted state. In other states (e.g., engine braking operation), the folding mechanism 118 is controlled to assume the retracted (folded or unlocked) state and the extension mechanism 116 is controlled to maintain its extended state. In this manner, the extension mechanism 116 and the folding mechanism 118 allow the various valve actuation operations to be lost or carried through the rocker arm 102, depending on the desired operating conditions, e.g., according to positive power or engine braking. do.

As shown, the extension mechanism 116 is configured to carry valve actuation operations to the one or more engine valves 108. More specifically, and as further illustrated in the various examples described below, the extension mechanism 116 is configured to couple auxiliary valve actuation operations, resulting from the auxiliary valve actuation operation source 106, to one or more engine valves (not shown) 108 < / RTI > In one embodiment, the elongation mechanism 116 is configured to engage only one of the one or more engine valves 108, such as in the case where the valve bridge has a sliding pin that engages one of the engine valves, And is configured to carry auxiliary valve actuation operations to the valve.

As also shown in FIG. 1, the folding mechanism 118 is configured to receive the main valve actuation operations from the main valve actuation operation source 104. In an embodiment, the folding mechanism includes a contact surface for receiving operations from the main valve actuation source 104. As used herein, the contact surface may comprise any means used to accommodate these operations. For example, when the main valve actuation source 104 is embodied by the cam of the overhead camshaft, the contact surface of the folding mechanism 118 may comprise a cam roller, a tappet, or a folding mechanism configured to receive motion directly Surface. Alternatively, when the primary valve actuation operating source 104 is a push rod, the contact surface may include ball or socket actuation. The present disclosure is not limited by the specific configuration of the contact surface used by the folding member 118. [

As also illustrated in Figure 1, the rocker arm 102 is fixedly mounted to the operative receiving end 112 in the first embodiment and configured to receive auxiliary valve actuating operations from the auxiliary valve actuating source 106 (124). The fixed member 124 is different from the folding mechanism 118 in that it is not extendable or retractable, i.e. is formed rigidly. As illustrated in the following examples, the fixed member 124 can not receive operations from the auxiliary valve actuation operation source 106 when the folded member 118 is extended, but the folded member 118 is retracted May be configured to receive operations from an auxiliary valve actuation operation source 106 (when folded or unlocked). As with the folded member 118, the fixed member 124 includes a contact surface for receiving supplemental valve actuation operations, which may likewise take any of the shapes described above. Once again, this disclosure is not limited by the particular configuration of the contact surface used by the stationary member 124.

1, the rocker arm 102 also includes a main valve actuator 126 at the valve actuation end 114 of the rocker arm 102. As shown in FIG. The primary valve actuator 126 is configured to carry the main valve actuation operations to the one or more engine valves 108. For example, the primary valve actuator 126 may include a so-called elephant foot or an e-foot configured to contact the valve bridge. Also, the primary valve actuator 126 may include a lash adjustment screw or the like, as is known in the art.

Finally, it should be noted that the particular order of the extension mechanism 116, the folding mechanism 118, the fixed member 124, and the main valve actuator 126 illustrated in FIG. 1 is not intended to be a requirement, The valve actuator 126 need not be positioned further away from the center of the rocker arm 102 than the extension mechanism 116.

Figure 2 illustrates a schematic block diagram of an apparatus 202 and a system 200 for operating engine valves in accordance with a second embodiment of the present disclosure. The system 200 is essentially the same as the system 100 illustrated in FIG. 2, with some significant exceptions. In particular, the system 200 includes a rocker arm 202, a main valve actuation source 104, an auxiliary valve actuation operation source 106, one or more engine valves 108, and one or more fluid supply sources 110, 110 '). However, in this second embodiment, both the folding mechanism 118 and the extension mechanism 216 are at the operative receiving end 112 of the rocker arm 202. [ As a result, the fixed member 124 is not included in the second embodiment. In this case, the main valve actuator 124 is used to carry not only the main valve actuation operations, but also the auxiliary valve actuation operations.

In this second embodiment, the extension mechanism 216 is configured to receive auxiliary valve actuation operations from the auxiliary valve actuation operation source 106. In this embodiment, the elongate mechanism 216 also includes a contact surface for receiving auxiliary valve actuation operations, which may likewise take any of the shapes described above. Once again, the present disclosure is not limited by any particular configuration of the contact surface used by the extension mechanism 216. [ Also in this second embodiment, a first fluid passage (not shown) that allows fluid communication between the fluid supply source (s) 110, 110 'and the elongation mechanism 216 to thereby control the operation of the elongation mechanism 216 (220) is provided. Once again, the particular sequence of extension mechanism 216 and folding mechanism 118 illustrated in FIG. 2 is not intended to be a requirement; for example, the extension mechanism 216 may be located at the center of the rocker arm 202 rather than the folding mechanism 118 Need not be located further away.

Through controlled retraction or extension of the extension mechanisms 116 and 216 and the folding mechanism 118 (through the first fluid passages 120 and 220 and the second fluid passages 122, respectively), the main and auxiliary valve movements Operations from both the operating sources 104 and 106 may be selectively lost or may be carried by one or more engine valves 108 by the rocker arms 102 and 202. Examples of such selective delivery of valve actuation operations are illustrated in Figs. 14 and 15. Fig. 14 and 15 (FIG. 14) and in combination with two-stroke engine braking and BGR mode (FIG. 15) selective valve lift application to the exhaust valve . In both Figures 14 and 15, the cam profiles / valve operations are plotted along a horizontal axis represented by the degree of crankshaft rotation. According to convention, two complete rotations of the crankshaft are illustrated from -180 degrees to 540 degrees, top dead center piston positions occur at 0 and 360 degrees, bottom dead center piston positions are 180 and 540 (-180) degrees, Fig. Also consistent with the convention, the crankshaft rotation between -180 degrees and 0 degrees corresponds to the compression face; Rotation between 0 and 180 degrees corresponds to a power or expansion phase; Rotation between 180 degrees and 360 degrees corresponds to the exhaust face; And rotation between 360 degrees and 540 degrees (-180 degrees) corresponds to the inspiratory phase.

In this context, Figure 14 illustrates the main exhaust valve lift 1402, which occurs primarily during the exhaust phase, as is known in the art. According to the first and second embodiments described above, when the folding mechanism 118 is in the extended or locked state, the main exhaust valve lift 1402 provided by the main valve operating source 104 is generated (That is, carried to the exhaust valve 108 through the rocker arms 102, 202). The profile of the auxiliary valve actuating operation source 106 is illustrated in Figure 14 and in this example includes two decompression engine braking lobes 1404 and 1406 (thereby providing two-stroke engine braking) and two BGR lobes (1408, 1410). These auxiliary operations, however, are not carried (i.e., they are lost) to the exhaust valve 108 due to the retracted or unlocked extension mechanisms 116, 216. In contrast, FIG. 15 illustrates the state of the folding mechanism 118 that is retracted or remains unlocked, such that the main exhaust valve lift 1402 is lost, as indicated by the dashed lines. Simultaneously, the extension mechanism 116 allows the operations 1404, 1406, 1408, 1410 provided by the auxiliary valve actuation operation source 106 to be performed by the compressor-release valve operations 1504, It is extended to be carried as the operations 1508 and 1510 or remains locked. While Figures 14 and 15 illustrate particular examples of valve lifts consistent with this disclosure, those skilled in the art will appreciate that a variety of primary and secondary valve operations may be performed in accordance with the teachings herein.

Various implementations of the first and second embodiments of FIGS. 1 and 2 are now described below with respect to FIGS. 3-12.

Figures 3 and 4 illustrate a perspective and bottom perspective view, respectively, of the implementation of the rocker arm 302 in accordance with the first embodiment of Figure 1. As in FIG. 1, the rocker arm 302 has an operational receiving end 112 and a valve movable end 114. The rocker arm 302 has a rocker arm shaft bore 330 formed therein, which is configured to receive the rocker arm shaft 502 (FIG. 5). The dimensions of the rocker arm shaft bore 330 are selected to allow the rocker arm 302 to rotate reciprocally about the rocker arm shaft 502. One or more supply ports (not shown) form a rocker arm shaft bore 330, and a fluid provided by one or more fluid channels formed in the rocker arm shaft 502, And may be formed on an inner surface that is positioned to receive engine oil.

The operational receiving end 104 of the rocker arm 102 is configured to receive valve actuation operations from both the main valve actuation source and the auxiliary valve actuation source (not shown) through their respective contact surfaces. In the illustrated embodiment, the contact surfaces include a main cam roller 332 and an auxiliary cam roller 332, such as when the primary and auxiliary valve actuation operation sources 104,106 include cams on the overhead cam shaft (334). In the illustrated embodiment, the primary cam roller 332 is attached to the folding mechanism 318 while the secondary cam roller 334 is attached to the fixed member 324. As shown, cam rollers 332 and 334 can be attached to these respective components through cam roller axles. However, as will be appreciated by those skilled in the art, and as noted above, the cam rollers 332 and 334 may be replaced by tappets configured to contact, for example, an overhead cam. In another alternative, the rollers may be replaced by a ball or socket run, as in the case where the primary and auxiliary valve actuation operating sources 104, 106 include push rods. Again, this disclosure is not limited in this respect.

As shown, the folding mechanism 318 may include a boss extending transversely from the rocker arm 302 having a bore formed therein. In the bore of the folding mechanism 318, the folding piston 319 is disposed. In an embodiment, the folding piston 319 may be implemented as an external plunger of a wedge locking mechanism. Such a wedge lock mechanism is described in U. S. Patent Application Serial No. 10 / 021,253, filed July 15, 2014, entitled " Lost Motion Valve Actuation Systems With Locking Elements Including Wedge Locking Elements " "'982 application"), the teachings of which are incorporated herein by reference. As described herein, embodiments of the wedge lock mechanism applicable to the present disclosure include one or more wedges arranged to engage an external recess formed in the housing and disposed in the lateral openings of the outer plunger. In the absence of fluid movement, the spring bias applied to the inner plunger disposed in the outer plunger forces one or more of the wedges to radially project from the outer plunger and is locked to engage the outer recess of the housing, Lock the outer plunger against. Applying the actuating fluid to the inner plunger sufficiently to overcome the spring bias applied to the inner plunger permits one or more of the wedges to be disengaged from the outer recess of the housing, thereby causing movement of the outer plunger relative to the housing .

In the context of this disclosure, when the folding piston 319 is implemented as an external plunger of the '982 application, the member of fluid in the second fluid passage 122 (not shown) is configured such that the folding piston 319 engages the folding mechanism 318, Lt; RTI ID = 0.0 > boss < / RTI > Conversely, the supply of fluid to the second fluid passageway 122 causes the wedge lock mechanism to be unlocked, thereby allowing movement of the folding piston 319 relative to the boss, i.e., the folding piston 319 Any operation that is unlocked and applied to it will be lost.

In another implementation, a coincidental approach is proposed, filed on September 24, 2013, entitled " Integrated Lost Motion Rocker Brake With Automatic Reset "(" Various embodiments of locking mechanisms, such as those described in U.S. Patent Application Serial No. 14 / 035,707, the teachings of which are incorporated herein by reference, can be used to implement the folding mechanism 318. In this case, the folding piston 319 can be carried out by a movable piston as taught herein, which engages with a spring-biased, fluid-actuated locking piston. In one position where no actuating fluid is applied to the locking piston, the locking piston is forced into the recess formed in the locking piston by the actuator piston (under bias of the spring), whereby the actuator piston is retracted relative to its housing Lt; RTI ID = 0.0 > a < / RTI > actuator piston. Conversely, application of the moving fluid causes translational movement of the locking piston such that the actuator piston is displaced from the recess and locked in its extended position relative to its housing.

Thus, in the context of this disclosure, when the folding piston 319 is implemented as an actuator piston of the '707 application, the member of fluid in the second fluid passage 122 is such that the folding piston 319 is biased against the boss of the folding mechanism 318 To be unlocked. Conversely, the supply of fluid to the second fluid passageway 122 causes the locking mechanism to be locked, thereby preventing movement of the folding piston 319 relative to the boss. It should be noted that the control of each of the locking mechanisms taught by the '982 and' 707 applications is reversed; Applying the control fluid to the locking device of the '982 application causes the locking device to be unlocked and the absence of the control fluid causes the locking device to be locked, while applying the control fluid to the locking device of the' 707 application Causes the locking device to be locked and the absence of the control fluid causes the locking device to be unlocked.

The main valve actuator 326 is located relatively farther along the valve actuating end 114 of the rocker arm 302 than the elongate mechanism 316, as also shown in Figures 3 and 4. In the illustrated embodiment, the primary valve actuator 326 includes a so-called "elephant foot " screw assembly 340 that includes a lash adjustment nut. Those skilled in the art will appreciate that the primary valve actuator 326 may be implemented using other well-known mechanisms for coupling valve actuating operations to one or more engine valves. As with the folding mechanism 318, the extension mechanism 316 may include a boss formed in the valve movable end 114 and having a bore formed therein in which the piston 762 (Figs. 4 and 7) is disposed. The implementation of the extension mechanism 316 is illustrated in FIG. 7, wherein the extension mechanism 316 is illustrated in cross-section. As shown in FIG. 7, the extension mechanism 316 includes a lash adjustment screw 763 that is deployed in the bore 760. A piston 762 is located at the end of the lash adjustment screw 763 and at the open end of the bore 760. The spring 764 biases the piston 762 into the bore 760 due to its deployment between the screw 763 and the ring 766 attached to the piston 762 as shown. The bore 760 is also in fluid communication with the first fluid passageway 712. The bias of the spring 764 causes the piston 762 to assume a retracted position within the bore 760 when fluid is not being supplied to the bore 760 by the first fluid passageway 712. Conversely, when fluid is applied to the first fluid passageway 712 and the bore 760, the force of the spring 764 is overcome and the piston 762 extends beyond the bore 760.

As is known in the art, it is sufficient to cause the piston 762 to extend beyond its bore 760, but applying low pressure fluid is not sufficient to withstand the valve actuation forces exerted on the rocker arm 302 . However, as is well known in the art, the control valve 336 may be utilized to hydraulically lock fluid to the first fluid passageway 712 and the bore 760, and thereby also to the rocker arm 302 Thereby locking the piston 762 to a degree sufficient to withstand the valve actuation forces applied. The control valve may be considered as an interior portion of the fluid supply source (s) 110 'in that the control valve 336 helps to supply fluid to the first fluid passageway 712. 3, the control valve housing 132 may be laterally aligned with respect to the longitudinal axis of the rocker arm 302, although this is not a requirement. As will be described in greater detail below, the control valve 336 encompasses a check valve used to adjust the flow of hydraulic fluid into the hydraulic circuit in fluid communication with the bore forming the elongation mechanism 316. A further discussion of control valve 336 is provided below with respect to Figures 8-10.

As described above, the extension mechanism 316 may be implemented as an actuator piston 762 that operates in conjunction with the control valve 336. [ However, it is understood that this is not a requirement. Indeed, the various locking mechanisms described above for the folding mechanism 318 may be used equally to implement the extension mechanism 316. [ An advantage of the previously described locking mechanisms is that they can achieve a locked condition entirely on the application of low pressure fluid (or removal), thereby eliminating the need for the high pressure fluid circuit provided by the control valve 336 I will remove it.

Referring now to Figures 5 and 6, side views of the implementations of Figures 3 and 4 are shown, illustrating the operation of the rocker arm 302. [ In particular, the rocker arm 302 is mounted to a rocker arm shaft 502, which in the illustrated embodiment includes a first fluid supply source 726a and a second fluid supply source 726b. The use of the first and second fluid supply sources 726a, 726b for controlling the operation of the extension mechanism 316 and the folding mechanism 318 is further described below with respect to Fig. As also shown, the rocker arm 302 is configured to contact the valve bridge 508 through the main valve actuator 324. [ The valve bridge 508 then contacts both the first engine valve 512 and the second engine valve 514. The valve bridge 508 further includes a sliding pin 510 that is aligned with both the first engine valve 512 and the piston 762 of the extension mechanism 316.

FIG. 5 illustrates operation of the rocker arm 302 during positive power generation. As a result, the folding piston 309 is illustrated in its fully extended position so that the main cam roller 332 contacts the main valve operating source (i.e., the main cam; not shown) while the fixed member 324, The auxiliary cam rollers 334 at the ends of the cam followers are held away from the auxiliary valve actuation source (i.e., ancillary cam; not shown). At the same time the piston 762 of the extension mechanism 316 is held in its fully retracted position such that the lash space 516 is held between the piston 762 and the sliding pin 510. As a result, the fixed member 324 (and consequently, the rocker arm 302) does not receive any valve actuation operations from the auxiliary valve actuating source while the folding mechanism 318 (and consequently , Rocker arm 302) receives valve actuation operations from the main valve actuation source. The main valve actuation actions imparted to the rocker arm 302 are provided only through the primary valve actuator 324 and the valve bridge 508 to the first And second engine valves 512 and 514, respectively.

However, during operation of the rocker arm during the auxiliary operating mode (i.e., other than the generation of positive power), the folding piston 309 (not shown), as illustrated in FIG. 6, is allowed to retract into the folding mechanism 318 Which causes all operations from the main valve operation source to be lost relative to the rocker arm 302. [ At the same time, the piston 762 of the extension mechanism 316 is locked into its extended position to contact the sliding pin 510. As a result, a lash space 616 is formed between the main valve actuator 324 and the valve bridge 508. This contact between the piston 762 and the sliding pin 510 causes the rocker arm 302 to rotate so that the auxiliary cam roller 332 remains in contact with the auxiliary valve actuation source Clockwise). As a result, the fixed member 324 (and, consequently, the rocker arm 302) receives valve actuation operations from an auxiliary valve actuation source while the valve actuation operations from the main valve actuation source It is lost as mentioned. In this case, the auxiliary valve actuation actions imparted to the rocker arm 302 are only transmitted to the first engine valve 512 through the sliding pin 510 and the piston 762 of the elongation mechanism 316. There is provided a lash space 616 maintained between the main valve actuator 324 and the valve bridge 508 and any of the auxiliary valve actuation operations are applied to the valve bridge 508 and consequently to the second engine valve 514 ≪ / RTI >

In the embodiments of Figures 5 and 6, first and second fluid supplies 726a and 726b are provided. Referring now to Figure 7, the use of first and second fluid supplies 726a, 726b is also described. In particular, the first and second fluid supplies 726a, 726b may be used as independent controls of the extension mechanism 316 and the folding mechanism 318, respectively. 7, the folding mechanism 316 includes an actuator piston 762 that operates in conjunction with the control valve 336, while the folding mechanism 318 is described in the '982 application And a wedge lock mechanism of the type described in U.S. Pat. Thus, as shown, the control valve 336 is in fluid communication with the bore 760 through the first fluid passageway 712 while the folding mechanism 318 is in fluid communication with the second fluid passageway 714. The first fluid supply passage 728 provides fluid communication between the first fluid supply source 726a and the control valve 336 while the second fluid passage 714 provides fluid communication between the second fluid supply source 726a and the control valve 336, Fluid communication. This distinction between the first fluid passageway 712 and the second fluid passageway 714 (i.e., communication through the control valve 336 or direct communication with these respective fluid supply sources 726a, 726b) Reflects the fact that the actuator piston embodiment of the mechanism 316 requires a high pressure circuit such as that provided downstream of the control valve 336. [

As also shown in FIG. 7, the provision of fluids through the first and second fluid supply sources 726a, 726b is controlled, for example, by respective solenoids 740a, 740b, respectively. Each solenoid 740a, 740b is connected to a common low pressure fluid source 750, such as engine oil. As is known in the art, solenoids 740a, 740b allow fluid to flow from a common fluid source 750 to respective first and second fluid supply sources 726a, 726b of rocker arm shaft 502 (Such as via an appropriate processor, such as an engine controller (not shown)) to allow the flow of fluid to flow. Thus, given the above-mentioned assumptions regarding the implementation of the extension mechanism 316 and the folding mechanism 318, and when fluid is not supplied by the first or second fluid supply sources 726a, 726b, The retention mechanism 316 will remain in its retracted state and the folding mechanism 318 will be locked in its extended state. When the fluid is allowed to flow by the first solenoid 740a through the first fluid supply source 726a, the elongate mechanism 316 will be locked in its extended state (actuation of the control valve 336) through). Independently, when fluid is allowed to flow by the second solenoid 740b through the second fluid supply passage 726b, the folding mechanism 316 will be unlocked so that the folding piston 319 is retracted It is allowed to take a state. Once again, as mentioned above, the control sensors of fluid supply sources 726a, 726b (i.e., fluid member = extended, fluid present = retracted, and vice versa) Folding mechanism 318, which can be chosen as a matter of design choice.

In an embodiment, prior to, or at least not later than, the beginning of the actuation of the folding mechanism 318 (i.e., to take its unlocked or retracted condition), the movement of the elongate mechanism 316 , Thereby avoiding the risk of losing all valve opening operations prior to a complete shutdown of the fuel to the cylinder during transition from positive power generation to engine braking, for example in the case of an exhaust valve do. For example, referring to FIGS. 14 and 15, the presence of the increased lift BGR valve operation 1410, 1510 ensures this "fail safe" exhaust valve opening. 7, the required timing is achieved by virtue of solenoids 740a, 740b being independently controlled, i. E. Fluid for at least some period of time prior to controlling second solenoid 740b to allow fluid flow. Lt; RTI ID = 0.0 > 740a < / RTI > 8 and 9, however, the control valve 336 may be operated according to a single switch type (i. E. Controlled by a solenoid, etc.) fluid supply and still maintain the desired timing referred to herein Can be achieved. In this embodiment, rather than being coupled directly to the second fluid supply source 726b, the second fluid passageway 714 is in fluid communication with the control valve 336, as described below. The advantage of the implementation illustrated in Figures 8 and 9 is then that the control valve allows for preferred control of the extension and folding mechanisms 316, 318 using only a single fluid supply source.

Figure 8 illustrates a control valve 336 according to an embodiment in which a single fluid supply source is used to provide a staged or timed fluid supply to the extension and folding mechanisms 316 and 318 described above. Sectional view. As illustrated, the control valve 336 includes a check valve having a check valve ball 802 and a check valve spring 804. The check valve ball 802 is biased to contact the check valve seat 806 by the check valve spring 804, that is, it is eventually secured to the retaining ring. As also shown, the check valve is in fluid communication with the first fluid supply passage 728. In the illustrated embodiment, the check valve is in the control valve piston 810, which is disposed within the control valve bore 812 formed in the control valve boss 800 itself. The control valve spring 820 is also disposed within the control valve bore 812, thereby biasing the control valve piston 810 in the rest position (i.e., toward the left in FIG. 8). The washer and retaining ring are used to retain the control valve spring 820 in the control valve bore 812 and to retain the control valve spring 820 for hydraulic fluid to exit the control valve housing 800, May be provided opposite the control valve piston 810 to provide a path.

The fluid in the first fluid supply passage 728 is sufficiently pressurized to overcome the bias of the check valve spring 804 to cause the check valve ball 802 to be displaced from the seat 806, To flow into a first circumferential, annular channel 816 that flows into the transverse bore 814 formed in the control valve piston 810 and thereafter also formed in the control valve piston 810. Simultaneously, the presence of fluid in the fluid supply passage 808 causes the control valve piston 810 to overcome the bias provided by the control valve spring 820, whereby the first annular channel 816 The control valve piston 810 is displaced (to the right in Fig. 8) to start establishing fluid communication with the second, circumferential annular channel 818 formed in the inner wall forming the control valve bore 812 ). Once the fluid communication between the first annular channel 816 and the second annular channel 818 begins, the fluid flows through the first fluid passageway 712, which is in fluid communication with the second annular channel 818 as shown, So that it is free to charge it.

While in its rest position and also when the first and second annular channels 816 and 818 begin fluid communication first, the control valve piston 810 is in fluid communication with the first fluid supply passage 728 and the second fluid passage < RTI ID = 0.0 > (714 '). The control valve piston 810 continues to displace under the pressure of the fluid from the first fluid supply passage 728 so that the trailing edge 822 is consequently displaced from the second fluid passage 714 ' To thereby provide fluid communication between the first fluid supply passage 728 and the second fluid passage 714 '. As a result, the second fluid passage 714 'starts to be charged by the fluid after the first fluid passage 712 starts to be filled with the fluid. Figure 9 illustrates a point when the control valve piston 810 reaches a hard stop and is no longer able to displace. At this point, the first and second annular channels 816, 818 are substantially aligned and the trailing edge 822 no longer provides any obstacles to the second fluid passage 714 '. As will be appreciated by those skilled in the art, the configuration of the trailing edge 822 as well as the strength of the control valve spring 820 with respect to the incoming pressurized fluid is determined by the start of fluid flow into the first fluid path 712, Lt; RTI ID = 0.0 > 714 '. ≪ / RTI >

Once the first and second fluid passages 712 and 714 'are filled, the pressure gradient across the check valve ball 802 will be the same so that the return valve ball 802 is re- seat, thereby substantially preventing the hydraulic fluid from escaping from the first fluid passageway 712. In view of the relative incompressibility of the fluid, the filled first fluid passageway 712 combines with the now filled bore 760 and provides an action (e. G., An auxiliary valve actuation source 106 Essentially establishes a rigid connection between the control valve piston 810 and the actuator piston 762, such as to be transmitted to the sliding pin 510 through the actuator piston 762. [ At the same time, the fluid in the second fluid passage 714 'remains at a lower pressure in the first fluid supply passage 728. The presence of the low pressure fluid of the second fluid passage 714 'unlocks the wedge lock mechanism, whereby the folding piston 319, This allows it to retreat.

8 and 9 illustrate how control valve 336 can be used to provide a fixed member 324 with a lubricant (if the fluid provided to control valve 336 includes, for example, engine oil) Also illustrated. As shown, additional fluid passageways 780 may be provided that diverge from the second fluid passageway 714 ', which additional fluid passageway 780 may communicate with the contact surface of the stationary member 324 do. In this manner, filling the second fluid passageway 714 only when desired lubrication is required is achieved by providing the folding mechanism 318 such that the contact surface of the stationary member 324 contacts the source of an auxiliary valve actuation operation. Lt; RTI ID = 0.0 > unlocked < / RTI >

A reduction in the pressure present with respect to the control valve piston 810 causes the control valve spring 820 to once again release the control valve piston 810 Lt; / RTI > to its rest position. This results in the reduced diameter portion 826 of the control valve piston 810 being aligned with the second annular channel 818 so that the hydraulic fluid in the first fluid passage 712 is in fluid communication with the control valve bore 812 To be released out of the open end of the opening. The depressurization of the first fluid passage 712 breaks the hydraulic lock between the control valve piston 810 and the actuator piston 762 thereby allowing the actuator piston 762 to once again assume its retracted position. When the trailing edge 822 of the control valve piston 810 once again closes the second fluid passage 714 ', the pressurized fluid in the first fluid supply passage 728 flows into the second fluid passage 714' It is no longer possible to flow in. The presence of the leakage paths in the folding mechanism 718 to which the second fluid passage 714 'is connected is now such that the fluid that is trapped in the second fluid passage 714' is provided by the control valve piston 810 Allowing to be drained more slowly compared to the quick depressurization of the first fluid path 712. When the fluid leaks out of the second fluid passage 714 ', the fluid pressure therein will eventually drop below a threshold, thereby causing the wedge locking mechanism of the folding mechanism 718 itself to be re-locked, RTI ID = 0.0 > 319 < / RTI > As described above, in this situation, the combination of the elongated folding mechanism 318 and the retracted extension mechanism 316 can be used to move the rocker arm (e.g., as provided by the main valve actuation source 104) To be transferred to the valve bridge 508 through the main valve actuator 324. [

As an alternative to the fluid delivery timing performed by the embodiment of Figs. 8 and 9, prior to, or at least not later than, the beginning of the actuation of the extension mechanism 316 (i.e., to take its extended state) (I. E., To take its unlocked or retracted condition) < / RTI > An example of a control valve 336 for this purpose is illustrated in Fig. 10, wherein like reference numerals designate like elements. However, in this implementation, the second fluid passage 714 "is configured to be filled by the fluid prior to filling the first fluid passage 712. More specifically, The filling of the second fluid passage 714 " will occur prior to displacement of the control valve piston 810 to an extent sufficient to allow fluid to flow into the first fluid passage 712 It is assumed that the bias of the valve spring 804 is overcome to enable the check valve ball 802 to be displaced from the seat 806). Once again, the relative stiffness of the control valve spring 820, as well as the configuration of the control valve piston 810 (i.e., the amount of displacement required prior to charging the first fluid supply passage 712) May be selected to provide a desired degree of delay between charges of each of the two fluid passages.

Referring now to Figures 11-13, an implementation in accordance with the second embodiment of Figure 2 is illustrated. 11 illustrates an exhaust rocker arm 1102 and an intake rocker arm 1103 having similar structures. As shown, both rocker arms 1102 and 1103 are in rocker arm shaft 1120 configured to supply fluid to rocker arms 1102 and 1103 in accordance with the techniques described above. Also, referring to the components of the exhaust rocker arm 1102, both of the rocker arms 1102, 1103 of the illustrated embodiment include an extension mechanism 1116 (not shown) on the operative receiving end 112 of the rocker arms 1102, And a folding mechanism 1118. Still further, the main valve operating source 1104 and the auxiliary valve operating source 1106 are illustrated as cams on the camshaft. As a result, the extension mechanism 1116 and the folding mechanism 1118 include contact surfaces in the form of cam rollers 1132 and 1134, respectively. Once again, the particular form of contact surfaces used by the extension mechanism 1116 and the folding mechanism 1118 will be dictated by the corresponding form of valve operating sources 1104, 1106. The advantage of the configuration of Figures 11-13 is that the relative compactness of the rocker arms 1102,1013 will not have an adequate space for two rockers for each of the exhaust and intake rocker arm practices Lt; RTI ID = 0.0 > and / or < / RTI >

12 and 13, a partial cross-sectional view of the exhaust rocker arm 1102 is shown. In particular, the extension mechanism 1116 includes a wedge lock mechanism of the type described in the '982 application, wherein the lock / unlock function provided by the first fluid path (not shown) is reversed. That is, as fluid is applied to the top of the inner plunger 1244 through the first fluid passageway, the increased diameter portion of the inner plunger 1244 is pressed against the outer plunger 1246 (as shown, Forces the wedges 1240 held in the corresponding recesses 1242 formed in the rocker arm 1102 to lock the outer plunger in the extended position. In this extended position, the auxiliary cam roller 1134 is kept in contact with the auxiliary valve actuation operation source 1106. [ 13, when the fluid is removed from the first supply passage, and consequently, from the top of the inner plunger 1244, the inner plunger causes the reduced diameter portion of the inner plunger 1244 to move away from the wedge Are biased upwardly by a spring to allow recesses 1240 to retract into outer plunger 1246 and thereby disengage with recesses 1242. [ Thus, the outer plunger, which is now unlocked, is now free to retreat so that the ancillary cam roller 1134 no longer maintains contact with the auxiliary valve actuation operation source 1106.

In the embodiment of Figures 11-13, the folding mechanism 1118 may instead be implemented using a control valve / actuator piston combination as described above. In this manner, filling of the second fluid passageway (not shown) will result in the folding mechanism 1118 being extended and hydraulically locked. Again, this is not a requirement, and the folding mechanism 1118 may also be implemented in a manner similar to the extension mechanism 1116. [

Figures 12 and 13 also illustrate the use of a hydraulic lash adjuster (HLA) incorporated in the rocker arm 1102. [ In particular, as shown, HLA is incorporated into the valve actuation end of the rocker arm 1102, although hydraulic supply connections for the HLA are not illustrated. As is known in the art, HLA allows automatic adjustment of the laceration space, thereby eliminating the need to manually adjust the laceration space. These HLA's may be used in connection with the first or second embodiments of FIGS. 1 and 2, at least in the manner depicted in FIGS. 12 and 13. FIG.

Although particularly preferred embodiments have been shown and described, those skilled in the art will appreciate that changes and modifications may be made without departing from the teachings herein. For example, the disclosure focuses on two main modes of operation, positive power generation and engine braking, where the relative states of the extension mechanism and the folding mechanism are always opposite each other, that is, when one is extended and the other is retracted . However, there are cases where it is desirable to keep both the extension mechanism and the folding mechanism in the same state. For example, in cylinder deactivation, it is desirable to completely remove the cylinder from positive power generation or engine braking. To this end, it is possible to lose both the main and auxiliary valve actuation operations, provided that both the extension mechanism and the folding mechanism are held in the retracted or unlocked condition. Conversely, if both the extension mechanism and the folding mechanism are maintained in an extended or locked state, if both the main and auxiliary valve actuation operations do not contradict each other or cause excessive valve opening, both the main and auxiliary valve actuation movements It is possible to do. It is therefore contemplated that any and all modifications, variations or equivalents of the above described teachings fall within the basic scope of the presently disclosed and underlying principles set forth herein.

Claims (21)

An apparatus for actuating one or more engine valves associated with an engine cylinder,
A rocker arm configured to reciprocate to actuate the at least one valve and having an operative receiving end,
A collapsing mechanism disposed at a motion receiving end of the rocker arm and configured to receive motion from a main valve actuation source,
An extension mechanism configured to carry an ancillary valve actuation operation to the at least one engine valve,
A first fluid passageway in communication with the extension mechanism, the supply of fluid to the first fluid passageway controlling operation of the extension mechanism, and
A second fluid passageway in communication with the folding mechanism, the supply of fluid to the second fluid passageway controlling the operation of the folding mechanism.
An apparatus for starting an engine valve. The method according to claim 1,
Wherein the extension mechanism is disposed at the valve operating end of the rocker arm,
An apparatus for starting an engine valve. 3. The method of claim 2,
Wherein the extension mechanism is configured to actuate only the first engine valve of the at least one engine valve,
An apparatus for starting an engine valve. 3. The method of claim 2,
Wherein the rocker arm further comprises a member fixed to an operating receiving end of the rocker arm, the fixed member comprising a contact surface configured to receive an operation from an auxiliary valve operating source,
An apparatus for starting an engine valve. 5. The method of claim 4,
Further comprising a control valve disposed in the rocker arm and configured to supply fluid to and check the first fluid passageway and to vent fluid from the first fluid passageway when the source of fluid to the control valve is removed,
An apparatus for starting an engine valve. 6. The method of claim 5,
Wherein the control valve is further configured to supply fluid to a contact surface,
An apparatus for starting an engine valve. A system for operating one or more engine valves,
The device of claim 4,
The main valve operating source, and
Comprising an auxiliary valve actuation operation source,
A system for operating an engine valve. The method according to claim 1,
Wherein the extension mechanism is disposed at an operational receiving end of the rocker arm and is configured to receive operation from an auxiliary valve operating source,
An apparatus for starting an engine valve. 9. The method of claim 8,
The extension mechanism including a contact surface configured to receive an operation from an auxiliary valve actuation source,
An apparatus for starting an engine valve. A system for operating one or more engine valves,
The apparatus of claim 8,
The main valve operating source, and
Comprising an auxiliary valve actuation operation source,
A system for operating an engine valve. The method according to claim 1,
Wherein the folding mechanism comprises a contact surface for receiving movement from a main valve actuation source,
An apparatus for starting an engine valve. The method according to claim 1,
Further comprising a control valve disposed in the rocker arm and configured to supply fluid to and check the first fluid passageway and to vent fluid from the first fluid passageway when the source of fluid to the control valve is removed,
An apparatus for starting an engine valve. 13. The method of claim 12,
Wherein the control valve is further configured to supply fluid to the first fluid path and the second fluid path,
An apparatus for starting an engine valve. 14. The method of claim 13,
Wherein the control valve is further configured to supply fluid to the first fluid passageway and then to the second fluid passageway.
An apparatus for starting an engine valve. 14. The method of claim 13,
Wherein the control valve is further configured to supply fluid to the first fluid passageway after supplying the fluid to the second fluid passageway.
An apparatus for starting an engine valve. 13. The method of claim 12,
Wherein the rocker arm is configured to receive a rocker arm shaft and wherein the rocker arm further comprises a fluid supply passage for providing fluid communication between the control valve and the fluid supply source of the rocker arm shaft,
An apparatus for starting an engine valve. 13. The method of claim 12,
Wherein the rocker arm is configured to receive a rocker arm shaft and wherein the rocker arm further comprises a first fluid supply passage for providing fluid communication between the control valve and a first fluid supply source of the rocker arm shaft,
The second fluid passage being in fluid communication with a second supply source of the rocker arm shaft,
An apparatus for starting an engine valve. The method according to claim 1,
Wherein the rocker arm further comprises a main valve actuator at a valve actuation end of the rocker arm configured to carry main valve actuation operations to the at least one valve,
An apparatus for starting an engine valve. The method according to claim 1,
The rocker arm is an exhaust rocker arm,
An apparatus for starting an engine valve. The method according to claim 1,
The rocker arm is an intake rocker arm,
An apparatus for starting an engine valve. The method according to claim 1,
Further comprising a hydraulic lash adjuster disposed at a valve actuation end of the rocker arm,
An apparatus for starting an engine valve.

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